1. Field of the Invention
The present invention generally relates to an attachment structure for a control key unit. More specifically, the present invention relates to an attachment structure for a control key unit to attach the control key unit to a cabinet of an audio-visual device, such as a television receiver.
2. Background Information
A conventional liquid crystal television receiver has a cabinet with a front cabinet and a rear cabinet. The front cabinet is rectangular when viewed from the front. The rear cabinet is coupled to the front cabinet. Key tops stick out from openings that are made at a plurality of locations aligned vertically in a side panel on one side of the front cabinet. The key tops are pressed by the user to set various modes. The key tops include a main power button, channel changing buttons, volume adjusting buttons, an external power switchover button, setup buttons, and other such necessary control buttons.
With the liquid crystal television receiver, a control key unit is attached to the side panel of the front cabinet.
The control key unit includes a wiring board and a frame. The wiring board is rectangular and vertically oriented. The frame is vertically oriented. The key tops are vertically arranged. The key tops are integrally formed from resin on the frame. The wiring board is temporarily fixed to the frame by positioning protrusions provided to the frame. The wiring board that is thus temporarily fixed is mounted to the frame with attachment screws. With the control key unit, a plurality of key switches mounted on the wiring board is individually disposed at the back of the key tops. The key tops stick out from a plurality of openings in the side panel of the front cabinet.
With the attachment structure for the control key unit, attachment tabs are provided to the ends of the frame in its lengthwise direction. The attachment tabs are fastened with attachment screws to bosses that are provided to the front cabinet, thereby attaching the control key unit to the side panel of the front cabinet. Therefore, it is absolutely necessary to use the attachment screws (two attachment screws, for example) to attach the control key unit to the front cabinet.
Meanwhile, various structures have been proposed in the past for attaching elements for performing operations, such as push buttons and control knobs, to a housing, casing, or the like without using any screws.
With a conventional structure, a plurality of buttons of a push-button cluster is positioned on a plurality of switches mounted on a wiring board and in a plurality of through-holes in a casing, respectively (see Japanese Laid-Open Patent Application Publication No. 2000-299567, for example). Specifically, with the structure, fitting holes, ribs with slits, or the like provided to the push-button cluster are combined with positioning pins, guide ribs, or the like provided to the casing having the through-holes, thereby positioning the buttons of the push-button cluster in the through-holes. Furthermore, slits provided to the wiring board are combined with ribs provided to the push-button cluster, thereby positioning the buttons of the push-button cluster at the switches.
With another structure, control buttons are attached to a casing without using any screws by installing ribs provided to control buttons on the bottom face of the casing, or engaging hooks provided to the ends of the ribs with slit grooves provided to the bottom face of the casing (see Japanese Laid-Open Patent Application Publication No. 2005-191029, for example).
With further another structure, a knob is attached from outside of a casing, which simplifies the attachment of the knob (see Japanese Laid-Open Patent Application Publication No. H6-36654, for example).
With further another structure, push buttons are mounted on a wiring board by engaging hooks provided to the push buttons with square attachment holes provided to a printed board on which push switches are mounted (see Japanese Laid-Open Utility Model Application Publication No. S61-54645).
With the attachment structure for the control key unit, when the attachment screws are used to attach the control key unit to the front cabinet, not only is the components cost higher because of the need for using the attachment screws, but the assembly process is more complicated because the time-consuming work of fastening the attachment screws has to be carried out. Accordingly, it is difficult to improve productivity.
In view of this, there is a need to be able to attach a control key unit to a television receiver by a simple method that does not entail the use of extra parts such as the attachment screws.
In regard to this, all of the above-mentioned structures merely propose a structure for directly attaching knobs or push buttons (as key tops) to a casing or wiring board. However, the structures cannot be directly employed as a structure for attaching the control key unit to a cabinet.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved attachment structure for a control key unit. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.